Electrically operated fluid flow controlling mechanism



P 1, c. e. KRONMILL ER 2,052,929

ELECTRICALLY OPERATED FLUID FLOW CONTROLLING MECHANISM Filed Oct. 27,1932 4 Sheets-Sheet l m N v n. or Keo M/L L EB fnve CARL 6 3184; 194%.

c. G. KRONMILLER Sept. 1, 1936.

ELECTRICALLY OPERATED FLUID FLOW CONTROLLING MECHANISM- Filed Oct. 27,1932 4 Sheets-Sheet 2 Jill/671L 01" EONM/L i CheL 61/1 LEI? ATTORNEY.

Sept. 1, 1936.

c. G, KRONMILLER 2,052,929 ELECTRICALLY OPERATED FLUID FLOW CONTROLLINGMECHANISM Filed Oct. 27, 1932 4 Sheets-Sheet 4 [rm/en 25oz" CAELGJKEONM/L use Patented Sept. 1, 1936 I UNITED STATES PATENT OFFICE2,052,929 ELECTRICALLY OPERATED FLUID FLOW CONTROLLING Carl G.Kronmiller Min to Minneapolis-Honeywell Regulator a corporation ofApplication October 27,

Minneapolis, Minn.,

MECHANISM neapolis, Minn., assignor Company, Delaware 1932, Serial No.639,815

19 Claims. (Cl. 137139) The present invention relates to an improvedother similar device.

5 vention relates to improvements in fluid flow conure of the supply ofelectrical energy.

One of the prior vices of the general character above referred to, isknown 'as a stalled motor motor and reduction gear train in the rection.

The power which is consumed during the time such train remainstationary.

One of the broader aspects of the present invention is the provision ofa fluid flow controlling element which is normally biased to oneposition, an electrical actuator including a reduction gear train whichmoves the biased fluid flow controlling element to a new position tricaldevice.

position against Another of the'important features of the invention isthe provision of means for disconnect- .ing part of the reduction geartrain from the biased fluid flow controlling element and preventingreverse rotation of the remaining portion of the gear train by a magnetor other elec- That is to say, the fluid flow conis moved to apredetermined its bias by an electrical motor as hereinabove described.When the fluid flow trolling element controlling element has reached itsnew position,

. tor bearings.

I comethis friction.

ing at the end of a reduction gear train, any

nates the possibility of trouble from sticky moif, by any chance, i

In addition, excessive friction should develop in that portion of thereduction gear train which is not disconnected from the motor, the wholeforce of the biasing means will be available to over- Furthermore, themotor befriction at the motor requires the use of more power to overcomeit than if the friction were present further gear train. As a result,the disconnection of part of the gear train greatly increases thereliability of operation of the fluid flow controlling element by itsbiasing means.

Past experience has shown that when a valve of the abovementioned typemoves to closed position, its movementis so suddenly stopped that boundsfrom or one-way connection,

which;

if the reduction gear train and other parts are permanently connectedthereto, the valve reis a very serious con dition if the valve iscontrolling the flow of gas to a burner, for instance. It has thereforebeen proposed .to provide an over-riding connection, or even a lostmotion connection between the valve and the reduction gear train so thatthe reduction gear train may continue rotating until its momentum isexpended after the valve has been closed by the biasing means.

A further object of the invention is the provision of an improved andsimplified, commercially feasible connection between a fluid flowcontrolling element, such as a valve, and a reduction gearing therefor,the connection being such. as to allow continued rotation of thereduction gear train after the valve has seated. V a

Still another object of the invention is the provision of means wherebya fluid flow controlling element, such as a valve, may be manually movedto and latched in a partial open position upon a failure in electricalpower and will resume automatic operation upon a restoration ofelectrical power. I

Another object of the invention resides in a general improvementthroughout the fluid flow controlling element operating mechanism. For amore complete understanding of the in vention, reference may be had tothe following description and accompanying drawings, in

Fig. 1 is a longitudinal cross-sectional view through a valve built inaccordance with the present invention, the valve being shown by fulllines in closed position and by dot open position,

Fig. 2 is a sectional view taken about on line Of Fig. 1,

Fig. 3 is a sectional view taken about on line 3-3 of Fig. 1,

ted lines in Fig. 4 is a sectional view taken about on line 5-4 of Fig.2,

Fig. 5 is a view similar to Fig. 4 but with the parts shown in the thevalve is open,

position they. assume when Fig. 6 is a sectional view taken about online 6-6 of Fig. 2 but with the valve manually latched in a partial openposition after a power failure,

Fig. 7 is a sectional view taken on about line 5-7 of Fig. 3 and showsthe electric magnet and associated parts in the posit when the magnet isdeenergized,

Fig. 8 is 'a view similar to magnet energized,

Fig. 9 is a view with parts in section showing a modified mechanism forpreventing rotation ion they occupy Fig. '7 but with the of the gearreduction train under certain condi tions,

Fig. 10 is a partial view showing the position of some of the parts ofFig. Q when the electric magnet is energized,

Fig. 11 is a schematic diagram of the manner in which the electricalconnections are made between the various electrical devices, and

Fig. 12 is a schematic view of a further modification.

Referring to the drawinga and more particularly to Figs. 1 to 8inclusive. the fluid flow con- -trolling element is herein illustratedas a valve,

generally indicated at at, which comprises a casing 2i that is providedwith an inlet port 22, and

outlet opening 23and a partition wall 25 between the inlet port 22 andoutlet opening 23. The

partition 26 is provided with receives a valve seat 25 upon whic disc 26is adapted to seat. The valve casing 2i is formed with an upwardlyextending externally threaded cylindrical portion 21.

an opening which h the valve A cup member 28 and a spring retainer 29are secured to opposite sides of a disc as the rivets Si.

30. by any suitable A bonnet member 32 which is means, such internallythreaded cooperates with the threads of cylindrical. portion 21inclamping disc 30 against the end of cylindrical portion Tito 10m Abushing 38 extends through spring retainer 2s, and

a fluid tight joint. cup member 28, disc 3U, into the valve casing H. asealing-off diaphragm An annulus 38 clamps against cup member 28. Avalve stem'36 carries valve disc 26 at its lower end,extends phragm 35,and ing 31 which is cover 33. The

through bushing 88 and diaterminates within a control casformed by theannulus 34 and a diaphragm 35 is secured to valve stem 36 in anysuitable fluid tight manner. The

and the other retainer 29. The mechanism thus far described constitutesa fluid flow controlling mechanism which includes a fluid flowcontrolling element that is biased to its minimum flow or closedposition by the compression spring 40.

Within the control casing 31 is a pair of vertically extending plates 4iand respectively generally indicated at any usual manner and comprises alaminated valve stem 36 carries a spring retainer .89 against which oneend of a compression spring 40 abuts end thereof abuts against spring 44is secured to plate 42 10 receives lever 58 besecondary air damper. Itwill be readily observed that as the valve disc 26 moves away from andtoward the valve seat 25, the outer free end of lever 58 will move downand up and this motion may of course be utilized to control some otherdevice whose" movement should be synchronized with the valve disc 26. Ifthe field coil 46 is now deenergized, the compression spring 40 willquickly move valve disc 26 into engagement with valve seat 25. Thismovement will pull link 63 in a downward direction rotating gear 66 andthe associated gears and motor rotor the end of rotor shaft 48 andhooked end 64 of link 63, however, form what might be termed aone-wayxzonnection so n-moved thereto will now be described. The gear 50is provided with a plurality of cone shaped projections 14 which projectlaterally from the gear 50 at points which are latch 16 and a plate I1,adapted to move into the 14 and the latter of which is adapted to engagegage stationary contacts upon the insulating sheet 85 and 86 mounted 82.An over-center The step-down transformer is provided with a. lowvoltagesecondary 94 one side of which is connected to one contact 95 of anysuitable type of automatic switch, such as a room thermostat generallyindicated at 96, by wires 91 and 98. The other contact 88 thermostat 96is connected to switch arm 84 by of the room ed by the moving side ofsecondary so by wires Hi2 and lot. Contact 86 is connected to one end ofcoil Bfl of the electric magnet 8! by wire ill and the other end of coil80 is connected to wire M3 by wire we.

If the room thermostat 96 should close con tacts 95 and 99, anenergizing circuit for motor will be established as follows: secondary9%, wire 91, wire 98, contact 95, contact 99, wire loll, switch arm 86,contact 85, wire ifli, motor it, wire I02, and W3 to secondary as.Energi'zation of motor will open the-valve through the reduction geartrain, link 83 and lever to as above described. When open position,switch arm 86 will be'snapped from engagement with contact 85 and intoengagement with contact 86. This will deenergize motor M andsubstantially instantaneously energize the 'coil 80 of electric magnet8| by a circuit which is as follows: secondary 94, 91, 98, 95, 99, mil,8%, contact 86, wire I0li,coil 80, wire Hi5, and lotto '94. Energizationof electric magnet 8i will at v tract armature 19 and rotate latchingmechanism 15 about its pivot to move latch 16 into the path ofprojections 14 and to cause plate ll to move rotor shaft 48longitudinally until pinion 6Q dls engages gear 50. When motor 45 wasdeenergized as above explained spring so will try to move valve disc 26downward into engagement with valve seat '25 and to rotate the reductiongear train in the reverse direction, but this will be preventoi latch 16into the path oi some one of the projections 14. When the roomthermostat opens contacts 95 and 99 coil 80 of electric magnet ill willbe deenergized and spring 18 will move latching mechanism It to theposition shown in Figs. 3 and '7 removing latch '56 from the path of theprojections it and moving plate ll from engagement with rotor shaft 38.The spring to will now move valve disc as into engagement with valveseat 25 and rotate the various gears in the reverse direction as previously explained. The motor rotor 61, however, will not be rotated sincepinion 69 has been moved out oi mesh with gear to. It will be noted byreference to Fig. 8 that the motor rotor 41 has been moved somewhat outof alignment with the laminated field 65. to motor 48 is next energized,the magnetic flux set up in laminated field will pull rotor 'B'fi intoalignment and the pinionda will again engage gear 50. I

A slight modification in the mechani for preventing reverse rotation ofthe gear reduction train and associated parts upon deenergiza= tion ofmotor 48 when the valveis open is shown in Figs. 9 and 10. In thismodification the gear 50a is not provided with any projections and thepinion 69a is made somewhat wider than the pining mechanism ion 89 inthe preferred construction. The latchwhich is adapted to engage the end0! rotor shaft 68a and move rotor 41a into engagement with a brakingdisc I08. This movement oi rotor shalt 68a is not sumcient to disengagepinion tea from gear 50a. In this modification, when the valve the motoris deenergized'and the electric magnet is energized as heretoforeexplained in connection with the preferred construction. Latchingmechanism lilo moves plate 51a into engagement with rotor shaft lsaso asto move rotor 410, against brake disc 36. Rotor tie is thereiorepreventedfrom rethe valve has reached its full .When the circuit willcontinue to open IE0 is provided with a plate We tating and since pinion59a is stfll in engagement with gear a the valve is maintained in openposition. When the electric magnet is deenergiaed rotor Ma is no longeri'orcibly held against brake disc I96 and the spring 60 is then free torotate the gear reductiontrain and the rotor 41a, in the reversedirection to close the valve.

Sometimes the supply of electrical power fail when the valve is open.From the above description, it will be obvious that under suchconditions the valve will close. It is desirable when there is a powerfailure to be able to open the valve manually and latch it in openposition in such a manner that it the power should return, the valvewill again be put under automatic electrical control.- The mechanism forobtaining these features will now be described. Referring particularlyto Figs. 2 and 6 it will be seen that a pin Mil which is provided withan enlarged head i8 is join-nailed in plate 42, extends throughinsulating sheet 82 and extends without the control case if! through anopening H19 in the cover 38. A coil spring liil has one of its endsabutting plate 42 and its other end abutting aninsulating bushing iiiwhich is mounted on pin I01 and prevented from longitudinal movementthereon by a clip H2. A contact arm H3 having a contact H6 is secured toinsulating sheet 82. A cooperating contact us which is carried by a con-.tact arm H6 is adapted to be moved into engagement with contact iilupoh inward movement of pin iill. If the power should be off and it isdesired to open the valve in such a manner that it will automaticallyreturn under automatic con-. trol when power is resumed, the extendedend of lever 58 is manually pushed down to open the valve and pin i9? ispushed path of movement of lever 58 so as to prevent iii) tends to movepin] iol to its original position but this is prevented by the enlargedhead IE8 enseeing the side of leverto. When the parts have beensooperated manually, the valve is in a partially open position andcontact H5 is in engagement with contact ill. Referring to" Fig. 11' itwill be noted that contact H6 is connected to wire M by a wire iii andcontact iii is connected to wire lilo by a wire lie. Contacts H4 and H5are therefore in shunt relationship with contacts 95 and 99. Now, if thepower should return, there will be an energizing circuit for motor assimilar to that above set out, but byway of contacts lit and lie insteadof contacts 95 and 89. Energization of motor M will open the valvefurther and lift lever -8 out of engagement with the enlarged head we ofpin till. Thespring ilil will therefore return pin it? to the positionof Fig. 2 wherein it will be out of the path of movement of the lever 58and contacts H6, H5 will be opened. If contacts 95 and 99 are closed atthis time, due to the room heing cold, the motor 44 the valve, altercontacts lit and H5 have opened, until the switch arm St is snapped iromengagement with contact 85 and into engagement with contact 86 whereuponthe valve will he maintained open by the energization of the coil 88 ofelectric magnet 8i as above brought out. If, however, contacts and 99are separated, the opening of contacts H4 and lid will prevent thecontinued energization pi motor 6t and the valve will return to closedposition ready for further automatic operation.

A iurther modification'showing another ma ner in which a fluid'fiowcontrolling element may i tained in a new position after having beer inuntil it is in the w is provided with a lost motion connection in theform of an elongated slot I25 which receives a pin I28 carried by a gearI21 at a point removed from its axis of rotation. The gear I21 is a partof a reduction gear train generally indicated at I20 which connects gearI21 with the rotor I29 01' a rotary electrical motor generally indicatedat I30. When the motor I30 is energized, gear I21 is rotated in aclockwise direction (as viewed in Fig. 12) and pin I20 engages the upperend of the slot I25 in link I24 to lift valve disc I2I away from valvecasing I20 to open the valve. In ,Fig. 12 the parts areshown with thevalve in open position.

The gear I21 carries a somewhat square shaped pin I3I removed from itscenter of rotation, which, during opening movement of the valve discI2I, engages the hooked end I 32 of a link I33 the other end of which ispivoted to an armature I34. The armature I 34 is pivoted at I35 on oneleg of a core I36 of an electric magnet which is provided with anenergizing coil I31. When the armature I34 has been so moved it is heldin the position shown by the energization of coil I31 and one of theflat sides I 38 of pin I3I abuts a flat portion I39 of the link I33whereby the valve open independently of the motor coil I31 is energized.When the coil I31 is deenergized, and if motor I30 is also deenergized,the biasing means move valve disc I2I to closed position rotating gearI21, in a counter-clockwise direction whereas to move armature I34 toits open position. A

spring I40 constantly about its pivot I4I whereby hooked end bemaintained in engagement with pin I3I.

When the valve disc I2I is again moved to its open position, thearmature I34 will again be brought to the position shown in Fig. 12 forthe purpose of maintaining the valve disc I2I in its open position asabove described. Obviously, the motor I30 and the coil I31 may beoperatively energized and deenergized at the proper and desired times inany suitable manner such as by the switching mechanism heretoforedescribed in the preferred construction.

From the above description, it will be apparent that the presentinvention provides a novel and improved manner of maintaining a biasedfluid flow controlling element in one position after the same has beenmoved thereto by a rotary motor and reduction gear train against itsbias. invention further provides for disconnecting a portion of the geartrain under certain conditions to render the ments in the one-wayconnection between the fluid flow controlling element and the reductiongear train, in the recycling mechanism and in the general construction.

While specific embodiments of the invention have been herein described,it is to be understood that many changes in details could easily bemade, and I intend to be limited only in the purview of appended claims.

I claim as my invention:

1. A device of the class described, comprising, in combination, a fluidflow controlling element biased to one position, an electricallyoperated actuator, a plurality of intermeshing gears operativelyconnecting the former to the latter through a projecting laterally fromone of said gears between said one way connection and said actuator, alatch movable into the path of said projecting elements, saidprojections beagainst its bias.

the class described, comprising, in combination, a fluid flowcontrolling element biased to one position, an electrically operment, anelectrically operated device for operating said means when the device isoperatively energized, and switching mechanism associated with the fluidflow controlling element for operatively energizing the electricallyoperated de vice and operatively deenergizing the electrically operatedactuator when the fluid flow controlling element has been moved to a newposition.

3. A device of the class described, comprising, in combination, a fluidflow controlling element position, a rotary electric motor, meansconnecting the motor and fluid flow controlling element including areduction gear train whereby the latter may be'moved to a new fluid flowcontrolling position against its bias by the former, an electric magnet,an armature therefor, a connection between the armature and movmovingthe former into the magnetic field of the electric magnet when the fluidflow controlling element is moved to its new position, the electricmagnet when operatively energized acting through the armature andconnection to hold the fluid flow controlling element in its newposition when the armaturehas been so moved by the moving means, and acommon source of power for the motor and electric magnet whereby thebiased fluid flow controlling element moves to its first position upon afailure of the common source of power.

4. A device of the class described, comprising,

plurality of intermeshing gears, an operative connection between one ofthe end gears and the rotary electrical motor, a laterally extendingprojection on the other end gear of the reduction one way connection, aplurality oi. elements secured to and biased to minimum gear train, saidprojection being spaced from the axis of rotation thereof, and a linkagesystem connected to the fluid flow controlling element and. having aportion in the path 01 movement of the projection to form an operativeconnec-- tion between the fluid flow controlling element and the rotaryelectrical former may be moved to maximum flow position by the latter.

5. A device or the class described,.comprising, in combination, a fluidflow controlling element flow position, a rotary electrical motor, areduction gear train including a plurality of intermeshing gears, anoperative connection between one of the end gears and the rotaryelectrical motor, a laterally extending projection on the other end gearof the reduction gear train, said projection being spaced from the axisof rotation thereoi, a linkage system 'ment, a reciprocatory reductiongear train in an intermediate connected to the fluid flow controllingelement and having a portion in the path of movement ot the projectionto form an operative connection between the fluid flow controllingelement and the rotary electrical motor whereby the former may be movedto maximum flow position by the latter, means for maintaining the fluidflow controlling element in its maximum flow position against its biasafter the motor is operatively deenergized, an electric magnet foroperating said means and switching mechanism operated by said linkagesystem for operatively deenergizing the motor and operatively energizingthe magnet when the fluid flow controlling element has been moved to itsmaximum flow position;

6. A device 01 the class described, comprising, in combination, a fluidflow controlling element biased to minimum flow position, a controlcasing associated with the fluid flow controlling elestem having one ofits ends operatively connected to the fluid flow controlling element andits other end extending into and terminating within the control casing,a lever pivoted withinthe control casing, one end of the leverterminating within the control casing and its other end extendingwithout the control casing whereby the lever may be utilized to operatean auxiliary device, means connecting said lever to said stem, anelectrical actuator, a comprising a plurality of intermeshing gears oneof which is operatively connected to the actuator, a lateral projectionon another or said gears and spaced from the axis of rotation thereof, alinkage connected to said lever near that end which terminates withinthe control casing and having a portion engageable by said lateralprojection, and a manually operable latch cooperative with the lever forlatching the fluid flow controlling element flow position when mam uallymoved to such position by manipulation of the extended end oifsaidlever.

'7. A device 0! the class described, comprising,

motor whereby the the motor,

connecting the former to shaft,

-ing, in combination, a

to, a reduction gearing connecting the pinion 6 to the valve, movablemeans for engaging the rotor shaft to disengage the pinion irom thereduction gear train and for duction gear train to prevent rotationthereof, an electric magnet for operating said means, and switchingmechanism associated with the valve for operatively energizing theelectric magnet and operatively deenergizing the motor when the valvehas been moved open position by 9. A device of the classdescribed,comprising, in combination,-a valve biased to closed position, a rotaryelectrical motor, a reduction gear train the latter, an electric magnetfor latching the valve in open position when moved to such position bythe motor, and a snap-action switching mechanism operated as a result ofmoving the valve from closed to open position for rapidly transferring asource of power from the motor to the magnet.

'11. A device of the class described, comprising,

in combination, a valve disc, a coiled spring biasing the same to closedposition, a control casing associated with the valve disc, a valve stemone end of which is connected to the valve disc and the other end ofwhich extends into and terminates within the control casing, a leverpivoted within the control casing, one end of the lever extendingwithout the control casing whereby it may be utilized to operate anauxiliary device and the other end thereof terminating within thecontrol casing, a member connecting the valve stem to the lever betweenits pivotal which terminates within the point and that end controlcasing, a link connected to that end of the lever that terminates withinthe control 7 casing, a rotary electrical motor, a reduction gear trainconnected thereto, and a one-way connection between the link and geartrain.

latter, means operated by the magnet tor main- 6 taining the fluid flowcontrolling element in anew position against its bias when movedthereand switching mechanism asso- -fluid flow controlling element to bythe motor, ciated with the for operatively energizing the magnet and op-7 eratively deenergizing the motor when the fluid iiow controllingelement has been moved to its new position.

13. A device 0! the class described, comprisfluidflow controlling ele- 1engaging the re- 10. A device of the class described, comprisa valvebiased to closed said motor including i Lil train by the biased fluidflow controlling mech- I anism, an electrically controlled device foroperating said means, and switching mechanism associated with the fluidflow controlling element for operatively energizing the electricallycontrolled device and. operatively deenergizing the field coil, themagnetic flux issuing from said motor field and. traversing the motorrotor serving to move the rotor into alignment therewith to re-engagethe pinion with the reductiongear train upon subsequent operativeenergizatlon or the field coil. I I

14. A device of the class described, comprising, in combination, a valvebiased to closed position, a rotary electrical motor for opening thevalve against its bias, said motor including a rotor shaft and a rotorsecured thereto, a memher having a braking surface adjacent the rotor,electrically operated means effective to-move the rotor into engagementwith the braking surface when energized, and switching mechanismassociated with the valve for operatively deenergizing the motor and foroperatively energizing the rotor moving means when the latter has movedthe valve to open position.

15. A device of the class described, comprising in combination, a fluidflow controlling element biased to one flow controlling position, alever, means pivotally mounting the same, means connecting said lever tosaid fluid flow controlling element at a, point spaced from the pivotpoint of said lever, a power operated actuator, a reduction gear trainconnected to said actuator, means including a one way connectionconnecting said gear train to said lever at a point spaced from thepoint at which said fluid controlling element is connected to said leverso that upon power being supplied to said actuator, said fluid flowcontrolling element is moved to a second flow controlling position, saidlever being provided with a portion adapted to be manually operated topermit said fluid flow controlling element to be manually moved tosubstantially said second flow controlling position upon power failure,said one way connection permitting such movement without movement ofsaid gear train and actuator, and a manually operable latch cooperativewith said lever for latching the fluid flow controlling element in saidlast named position.

16. A device of the class described, comprising in combination, a valvebiased to closed position, operating means movable in one direction foropening said valve against its bias, said valve moving the operatingmeans in the opposite direction on movement of the valve to closedposition due to its bias, the valve operating means having suflicientmass and being moved at such a rate of speed through a large enoughrange during valve closing movement, that the resulting momentum'wouldbe sufficient to cause the valve to rebound from closed position uponreaching the same, and a one way connection between the valve andoperating means for allowing unrestricted continued motion of the latterin valve closing direction after the valve has closed, said one wayconnection comprising a member associated with said actuator and movablethereby,-

which member has a projection extending therefrom, and a memberassociated with said valve and having a hook portion lying in the pathof movement of said projection.

'17. A device of the class described comprising, in combination, a fluidflow'controlling element biased to one flow controlling position, alever,- means connecting said lever to said fluidflow.

controlling element at a point spaced from the pivot point of saidlever, a power operated actuator, a reduction gear train, a connectionbetween said actuator and one end gear of said gear train, a connectionbetween said lever and the other and gear of said gear train comprisinga pin on said end gear and a member connected to said lever and having ahook portion engaging said pin upon rotation of said gear train due topower being supplied to said actuator so as to move said fluid flowcontrolling element to a second position against said bias, the bias ofthe valve being suflicient to return said element to said first positionand rotate the actuator and gear train in the reverse direction, saidconnection between said lever and said last named end gear permittingcontinuedirotation of said actuator and gear train until the momentumthereof is expended.

18. A device of the class described, comprising, in combination, anelement to be actuated, said element being biased in one direction to apredetermined position, an electrically operated actuator, a pluralityof intermeshing gears op eratively connecting said element to saidactuator whereby the former is moved in the opposite direction againstits bias upon energization of the latter, means for unmeshing two ofsaid gears and preventing rotation of the gears that are thereafterstill connected to said element, an electrically operated device foroperating said means when the device is operatively energized, andswitching mechanism associated with the fluid flow controlling elementfor operatively energizing the electrically operated device andoperatively deenergizing the electrically operated actuator when theelement has been actuated to a desired new position 19. A device'of theclass described, comprising, in combination, an element to be actuated,said element being biased in one direction to a predetermined position,a rotary electrical motor including a rotor shaft, a rotor thereon and apinion secured thereto, a reduction gear train connecting said pinion tosaid element, electrically operated means for moving said rotor shaft ina direction to move the pinion out of engage-v ment with the reductiongear train and to hold said reduction gear train against rotation, andswitching mechanism for operatively deenergizing the motor andoperatively energizing the electrically operated means when the elementhas been moved to a desired new position by the motor.

CARL G. KRONMILLER.

